About ExposureMath
ExposureMath is the camera arithmetic: the exposure triangle in working numbers, depth of field and hyperfocal distance, ND-filter stops, and the night-sky rules.
ExposureMath exists because photography is math wearing an art costume — stops, ratios, and inverse squares decide everything before taste does. The formulas are simple; having them at the scene is the difference between guessing and choosing.
Every calculator on ExposureMath shows its formula and its assumptions on the page, so you can check the math, reproduce it in a spreadsheet, or argue with it. Inputs are processed entirely in your browser — nothing is sent to a server, and there are no accounts.
ExposureMath is an independent, ad-supported project. We are not affiliated with any lender, brand, agency, or the sources we cite (established practice standards in the hobby). If a number looks wrong, the contact page reaches a human who fixes it.
What makes ExposureMath different
- Your numbers never leave your browser. Every calculator on ExposureMath runs entirely on your device. We never see, store, or transmit the figures you enter — there are no accounts and no server-side processing of your inputs.
- Published methodology. Each calculator page explains the exact formula it uses and the assumptions behind it, so you can check our work or reproduce it in a spreadsheet.
- Free, forever, without a paywall. ExposureMath is supported by advertising. There is no premium tier, no email gate, and no upsell.
Independence
ExposureMath is an independent educational project. We are not affiliated with, endorsed by, or acting on behalf of any government agency, lender, insurer, or the organizations whose formulas and public data we reference (such as established practice standards in the hobby). All trademarks and referenced standards belong to their respective owners.
Questions, corrections, or suggestions are genuinely welcome — get in touch.